Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
A-level
PHYSICS
Paper 1
Wednesday 20 May 2026 Afternoon Time allowed: 2 hours
Materials For Examiner’s Use
For this paper you must have:
Question Mark
• a pencil and a ruler
• a scientific calculator 1
• a Data and Formulae Booklet 2
• a protractor.
3
Instructions 4
• Use black ink or black ball-point pen. 5
• Fill in the boxes at the top of this page.
6
• Answer all questions.
• You must answer the questions in the spaces provided. Do not write 7–31
outside the box around each page or on blank pages. TOTAL
• If you need extra space for your answer(s), use the lined pages at the end of
this book. Write the question number against your answer(s).
• Do all rough work in this book. Cross through any work you do not want
to be marked.
• Show all your working.
Information
• The marks for questions are shown in brackets.
• The maximum mark for this paper is 85.
• You are expected to use a scientific calculator where appropriate.
• A Data and Formulae Booklet is provided as a loose insert.
*jun *
IB/M/Jun26/G4007/V9 7408/1
, 2
Do not write
outside the
Section A box
Answer all questions in this section.
0 1 . 1 ( )
Describe the simple model of the nitrogen-17 17
7 N atom.
[2 marks]
A nitrogen-17 nucleus is unstable and decays in two steps:
step 1
The nitrogen-17 nucleus decays to form an oxygen-17 17 ( )
8 O nucleus in an
excited state.
step 2
The excited oxygen-17 nucleus becomes a stable isotope by emitting a neutron.
0 1 . 2 State the fundamental force involved in step 1.
Go on to explain your answer.
[2 marks]
*02*
IB/M/Jun26/7408/1
, 3
Do not write
outside the
0 1 . 3 Describe, for step 2, the properties of the force that keeps the de-excited oxygen-17 box
nucleus stable.
[2 marks]
The neutron emitted in step 2 decays into a baryon and other particles.
0 1 . 4 State the names of the leptons that are produced in neutron decay.
[1 mark]
0 1 . 5 State the name of the baryon that is produced in neutron decay.
Go on to comment on the stability of this baryon.
[1 mark]
8
Turn over for the next question
Turn over ►
*03*
IB/M/Jun26/7408/1
, 4
Do not write
outside the
0 2 This question is about the photoelectric effect. box
Figure 1 shows an electroscope.
In this electroscope, the top of a gold leaf is attached to a metal rod. The metal rod is
attached to a metal cap.
When the cap is given a charge, the bottom of the leaf is repelled from the rod through
an angle θ as shown in Figure 1.
The greater the charge on the electroscope, the greater the angle θ.
Figure 1
In a demonstration, the cap is given a negative charge.
Monochromatic light is then incident on the cap.
When the light has a frequency less than a particular threshold frequency f0,
the angle θ does not change.
When the light has a frequency greater than f0, the gold leaf immediately falls back to
the rod so that θ is zero.
The cap is made from a metal M. The work function of M is 5.01 eV.
0 2 . 1 Explain what is meant by a work function of 5.01 eV.
[1 mark]
*04*
IB/M/Jun26/7408/1
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
A-level
PHYSICS
Paper 1
Wednesday 20 May 2026 Afternoon Time allowed: 2 hours
Materials For Examiner’s Use
For this paper you must have:
Question Mark
• a pencil and a ruler
• a scientific calculator 1
• a Data and Formulae Booklet 2
• a protractor.
3
Instructions 4
• Use black ink or black ball-point pen. 5
• Fill in the boxes at the top of this page.
6
• Answer all questions.
• You must answer the questions in the spaces provided. Do not write 7–31
outside the box around each page or on blank pages. TOTAL
• If you need extra space for your answer(s), use the lined pages at the end of
this book. Write the question number against your answer(s).
• Do all rough work in this book. Cross through any work you do not want
to be marked.
• Show all your working.
Information
• The marks for questions are shown in brackets.
• The maximum mark for this paper is 85.
• You are expected to use a scientific calculator where appropriate.
• A Data and Formulae Booklet is provided as a loose insert.
*jun *
IB/M/Jun26/G4007/V9 7408/1
, 2
Do not write
outside the
Section A box
Answer all questions in this section.
0 1 . 1 ( )
Describe the simple model of the nitrogen-17 17
7 N atom.
[2 marks]
A nitrogen-17 nucleus is unstable and decays in two steps:
step 1
The nitrogen-17 nucleus decays to form an oxygen-17 17 ( )
8 O nucleus in an
excited state.
step 2
The excited oxygen-17 nucleus becomes a stable isotope by emitting a neutron.
0 1 . 2 State the fundamental force involved in step 1.
Go on to explain your answer.
[2 marks]
*02*
IB/M/Jun26/7408/1
, 3
Do not write
outside the
0 1 . 3 Describe, for step 2, the properties of the force that keeps the de-excited oxygen-17 box
nucleus stable.
[2 marks]
The neutron emitted in step 2 decays into a baryon and other particles.
0 1 . 4 State the names of the leptons that are produced in neutron decay.
[1 mark]
0 1 . 5 State the name of the baryon that is produced in neutron decay.
Go on to comment on the stability of this baryon.
[1 mark]
8
Turn over for the next question
Turn over ►
*03*
IB/M/Jun26/7408/1
, 4
Do not write
outside the
0 2 This question is about the photoelectric effect. box
Figure 1 shows an electroscope.
In this electroscope, the top of a gold leaf is attached to a metal rod. The metal rod is
attached to a metal cap.
When the cap is given a charge, the bottom of the leaf is repelled from the rod through
an angle θ as shown in Figure 1.
The greater the charge on the electroscope, the greater the angle θ.
Figure 1
In a demonstration, the cap is given a negative charge.
Monochromatic light is then incident on the cap.
When the light has a frequency less than a particular threshold frequency f0,
the angle θ does not change.
When the light has a frequency greater than f0, the gold leaf immediately falls back to
the rod so that θ is zero.
The cap is made from a metal M. The work function of M is 5.01 eV.
0 2 . 1 Explain what is meant by a work function of 5.01 eV.
[1 mark]
*04*
IB/M/Jun26/7408/1
